This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Crohn's disease and ulcerative colitis are inflammatory bowel diseases (IBD) that are associated with systemic inflammation. This inflammation is in turn linked to poor appetite, growth failure and delayed puberty. Infliximab is a monoclonal antibody to TNF- that has recently been approved for use in pediatrics. Though it is known that long-term use of infliximab improves patients'quality of life (QOL), the short-term changes have not been studied. Additionally, it is not known whether infliximab improves levels of hormones related to growth and puberty. We propose to test for signs of inflammation-serum CRP and fecal lactoferrin-prior to, 2 days after and 2 weeks after an infusion of infliximab. We will also test for levels of hormones related to growth and puberty-including IGF-1, leutinizing hormone, estradiol and testosterone-and determine changes in measures of appetite and QOL. Such knowledge would be useful in defining normal response to therapy and in equipping physicians to titrate doses of infliximab and counsel patients regarding what to expect from treatment. Knowing the response of hormones related to growth and puberty will better characterize the effects of inflammation on these processes and help indicate whether infliximab might improve growth in children with IBD.